Hydraulic jack.



W. MESSINGER.

HYDRAULIC JACK.

APPUCATIONVFILED sEPT.2. |913.

PatentedSept. 7, l1915.

2 SHEETS-SHEET,I.

W/TNESSES:

W. MESSINGER.

HYDHAULIG JACK. i APPLlCATION FILED SEPT. 2.1913.

1,1 52,29. Patented Sept. 7, 1915.

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HYDRAULIC JACK.

Specification of Letters Patent.

raeenteasepe. 7,1915.

Application filed September 2,1913. Serial No. 787,556.

Philadelphia and State of Pennsylvania,

have invented certain new and useful Improvements in Hydraulic Jacks, ofwhich the following is a specification.

The principal object of the present invention is to provide a light,portable, compact or small, reliable and durable hydraulic jack whichshall be applicable for any purpose where great pressure isrequired andin which the working unit hydraulic pressure may be as high as twentythousand pounds per square inch or even higher.

Other objects of the invention will appear from the followingdescription and the invention will be claimed at the end hereof, butwill be first described in connection with the accompanying drawingsforming part hereof and illustrating one embodiment of the invention.

In the drawings, Figure 1 is a top view, principally in section, of ahydraulic jack embodying features of the invention. Figs. 2 and 3, arecentral sectional views drawn to an enlarged scale and illustrating thesuction and pressure valves respectively. Fig. 4, is a sectional viewtaken on Athe line 4 4 of Fig. 1. Fig. 5,f\i`s a similar view taken onthe line 5 5 of Fig. 1, and Fig. 6 is a sectional view on the line 6 ofFig. 5.

In the drawings 1, is a shell or casing provided with a liquid reservoir2 and with a pressure cylinder 3, completely separated from each otherby a partition 4. The shell or casing l is made from a bar of nickelsteel by boring the ends thereofto form the cylinder and chamber.

5, is a cap for inclosing the liquid reservoir and it is shown asprovided with a illing opening 6.

is the ram which works in the pressure cylinder 3. l

The walls of the cylinder 3, since the cylinder is made of'nickel steel,are thin and are subject to expansionv under the highworking unithydraulic pressure which can be carried to twenty thousand pounds, orhigher, per square inch. Tocompensate for the expansion in this cylinderwall use is y and collar 8 having a cone shaped sea-t into which fits ahollow cone 9 and both ofthese parts are interposed between the base ofthe cupleather 10 of the ram and the inner end of the ram 7. The area ofthe face of the cone 9, which is in contact with the cup leather, issuch and the cross-sectional area of the collar 8 is also such thatunder any pressure which may exist in the cylinder the unit stress inthe material of the collar will be identical with the unit stress in thecyline der walls, thereby making the expansion of the collar the same asthat lof the cylinder and so covering the clearance space produced byhigh pressure between the exterior of the ram and the bore of thecylinder. This prevents any extrusion of the cup leather past the ramunder the force of the high liquid pressure against the leather cup.There is, in fact, a coperation between the ldescribed wedge packingwith the thin sec` tion of the cylinder wall by which the use of nickelsteel is made possible and desirable, sothat the jack may be madecoinparatively small yet sulciently strong to be extremely powerful.

There are ports 11 and 12 disposed on opposite sides of the partition 4and leading from the liquid reservoir and the cylinder through the wallof the shell or casing l.

From the foregoing description it is evident that the liquid receptacleand the pres'- sure cylinder constitute a single piece or unitarystructure. 13, is a body detachably applied, as by means of screws tothis untary structure and containing the pump, its

operating mechanism and all the valves and their accessories of thedevice, so that in case of repairs, renewals or cleaning, the body 13can be detached and ready access had to the various parts which itcarries. Within the body 13 there is a bore or chamber closed by a cap14 and of relatively large and relatively small diameter. The chamber 15of relatively large diameter accommodates the rack portion 16 ofthe pumpplunger and the chamber 17 of relatively small diameter accommodates theplunger 18' proper. The parts 16 and 18 are connected together. Theplunger, as a whole, presents two working faces, a small one at the endof the part 18 and a larger one at the end of the part 16. The packing19 and packing a small working area is to provide for moving the ram 17rapidly with comparatively little power, for example, so as to get it inplace and slowly with comparatively great power so as to exert anenormous pressure. The plunger is reciprocated by means of a toothedwheel 23 that can be oscillated by means of a hand lever 24, or othersuitable appliance. There is in the body 13 a fluid channel 25, shown asformed by drilling the body in different directions and plugging up thedrill holes, although this is not material.

p There are formed through the inner face of the body two openingsarranged respectively on opposite sides of the partition 4 and alinedwith the openings 11 and 12 and communicating with one end of thepassage 25. These openings receive the suction valve 26 and the pressurevalve 27. Between the body and the casing and around the describedopenings are washers or rings 28. These consist of parchment paper, theparticular usefulness of which lies in the fact that it is not affectedby the action of water, oil or other liquid ordinarily employed inhydraulic jacks,land in the fact that it can be used to confineenormously high pressures by virtue of its own strength and because ofthe exceedingly small thickness in which it can be employed, therebyreducing to a minimum the total pressure which can act upon it tendingto ltear it open. The other end of the passage 25 communicates with thesmall bore 17 and with the large bore 15 of the plunger chamber behindthe small working face of the pump plunger and behind the large workingface of the pump plunger. There is a valve 29 having a handle 30 whichoperates to open and close communication between the passage -25 and thelarger working surface of the pump plunger. The purpose of this is thatwhen the valve is closed the small area of the pump plunger is eifectivefor slow motion of the ram, whereas when the valve is'opened the largearea of the pump plunger in addition to the small area, is elfective forrapid motion of the ram. The valve 29 is a needle valve. The handle isshown in Figs. 1 and 5 and the valve and its seat in Figs. 4 and 5. Theseat is at a, and the valve 29 lets passages 25 and into communicationor interrupts communication between them. The passage b is' shown inFig. 4v as formed partly in the casing and partly in thepacking ring 20and each part of it is lettered to facilitate following it. The innerend of the valve 29 is solid and the valve moves inward far enough toabut on theseat a and s0 cut off communication between 25 and b, Fig. 6,and the valve moves outward far enough to uncover the seat a and let 25and b communicate. In Fig. 5, the circle marked 25 is the end of thepassage directly in front of the valve. It might have been consideredremoved in making the section, but it is shown to aid the illustration.Fig. 6 shows how the passage 25 comes through the valve casing and maybe covered and uncovered by the valve, and it alsov shows how thepassage b is opened when the valve is olf its seat and is closed whenthe valve is on its seat.

31 and 32 are diagonal relief passages communicating with the liquidreservoir opening 11 and with the pressure cylinder opening 12 andby-passing the valves 26 and 27 and communicating with a passage 33,which may be opened and closed by the valve 34 having a handle 35, sothat by turning the handle 35 it is possible to by-pass the valves 26and 27 and establish communication between the liquid reservoir and thecylinder so as to permit of rapid motion of the ram 7 .into itscylinder. y

36, is a tube that may constitute an eXtension of the opening 11 andthrough which liquid passes from and to the reservoir.

Both the suction and pressure valves consist of a body 37 having acone-shaped shoulder 38, which by means of a thread 39 can be securedtightly against a corresponding conical seat in the opening in the pumpbody into which the valve body 37 is screwed. The portion 40 of thevalve body adjacent to the seat 38 is undercut so as to permit of freeseating and thus a perfect liquid tight joint is obtained without anypacking-material. The valve stems 41 are provided with a shoulder 42having a coneshaped face which fits a corresponding conical seat in thevalve body. The valve is guided by means of a long stern 43 which worksin a snugly fitting opening in the valve body. Theopening in the valvebody provided for thevalve stem is counter-bored for a short distancebelow the seat as shown at 44 and the conical face on the shoulder ofthe valve is also abruptly terminated, so as to make the cone portionsboth on the valve and its sea-t ofthe same length and co-incident whenthe valve is seated. 45 is a hole or opening drilled longitudinally intothe stem and communicating with cross-drilled openings 46 locatedadjacent to the seat. By this construction liquid always fills theannular recess created by the counter-bore and the instant that thevalve lifts off its sea-t the liquid is discharged instantly anduniformly all around the valve seat. This tends to prevent cutting ofthe seats which might otherwise occur from the high velocity lof theissuing stream if it were localized. The valve seats being formed inseparate pieces can be detached from the pump body and renewed withoutnecessitating any machine work or other operations on the pump. Theconstruction of both the pressure and the suction valves is the same,eX- cept that the direction of their seats is reversed and in the caseof the pressure valve grit or other foreign substance which mayv lindits way into the liquid medium employed to operate the jack is crushedunder the valves without scoring or injuring them and at the next strokeof the plunger the valve seats will be clear of the obstructingmaterials allowing the valve to become perfectly seated. Scoring or likeinjury of the valves would produce leakage and make the' jack difficultto maintain in operating condition. Again, hardened valves resistdistortion and hence operate successfully under such high unit hydraulicpressure as would distort valves made of such materials as have beenheretofore employed or suggested, thus rendering hydraulic jacksineflicient. Moreover the described substitution of material permits ofa great reduction in the size or area of the valves and, of course, areduction in the area or size of the valves means that the pressure towhich they are subjected and which tends to distort them is so reducedthat distortion is avoided. In other words, the described substitutionof material converts hydraulic jacks which have been substantialfailures for uses requiring their transportation and requiring greatstrength into jacks which are well adapted to .perform such uses andpurposes. The elastic limit of hardened steel is high, so that valvesand valve seats made of it can work under a high unit pressure withintheir elastic limit. In consequence, a valve or valve seat may'yield toconform to irregularities in either and thus make a tight valve, withoutany permanent distortion.

In use the pump plunger is reciprocated by the handle 24. According tothe position of the valve 29 either its large or small working surface-operates to draw liquidv from the reservoir 2 past the valve 26 intothe passage 25 and into the pump cylinder and to expel the same at eachreciprocation of the plunger past the valve 27 behind the ram. When highpressure is applied to the ram the wedge packing 8 9 equali'zes eX-pansion as has been described and permits the jack to operatenotwithstanding expanf sion of the walls of the pressure cylinder underthe great pressure to which they are subjected. The ram may be permittedto enter the cylinder by manipulating the valve 34 and thus establishingthe by-pass around the valves 26 and 27 and putting the cylinder intodirect communication with the reservoir.

It will be obvious to those skilled in the art to which the inventionrelates that modifications may be made in details of construction andarrangement without departing from the spirit of the invention.

What I claim is:

l. In a hydraulic jack the combination of a pump plunger having a largeand a small effective area, a ram and its pressure cylinder, fluidconnections from the ram to the small and to the large area, a valve forexcluding fluid from and affording it access to the large area and asingle pressure valve common to both areas. p

2. In a hydraulic jack the combination of a casing having therein aliquid reservoir and a pressure cylinder and their fluid outlets throughthe casing, a ram in the pressure cylinder, a pump body having therein amultiple speed pump, connections for each pump speed to the reservoirand pressure cylinder, a valve carried by the pump body for positivelyclosing one of said connections and a single pressure valve common toboth pump speeds.

3. In a hydraulic jack the combination of means including a singleautomatic pressure valve and a single automatic suction valve foroperating it at twof different speeds, and a single valve independent ofsaid valves for making one of the speeds both inoperative andineffective.

4. In a hydraulic jack the combination of a liquid reservoir andpressure cylinder, a pump operatively connected therewith, fluidpassages connecting the pump and reservoir and cylinder, and suction,and pressure valves and their seats interposed in the fluid passages.and both made of hardened steel which distorts under high unit pressuremaking irregularities in contact surfaces of the parts to conform,thereby insuring tightness and which recovers its original form whenreleased from such pressure, whereby the jack can be small and of greatpower.

5. In a hydraulic jack the combination of a pressure cylinder, a ram, anon-metallic packing, and a radially expansible packing interposedbetween the non-metallic v packing and the ram to prevent thenonmetallic packing from being forced between the bore of the cylinderand the surface of the ram.

6. In a hydraulic jack the combination of a pressure cylinder ofmaterial having a high elastic limit, a ram, a fibrous packing incase@screw-and-thread connections between th body and Valve seat.

8. In a hydraulic jack the combination of '15 a pressure cylinder, aram7 a cup packing on the ram and coperating conical rings between thecup packing and ram whereby expansion in the cylinder walls iscompensated for.

W'ILLAM MESSINGER. Witnesses:

CLIFFORD K. CAssEL, FRANK E. FRENCH.

